# A piggy bank contains hundred 50 p coins

Question:

A piggy bank contains hundred 50 p coins, fifty Rs 1 coins, twenty Rs 2 coins and ten Rs 5 coins. If it is equally likely that one of the coins will fall out when the bank is turned upside down, what is the probability that the coin

(i) Will be a 50 p coin?

(ii) Will not be a Rs.5 coin?

Solution:

Total number of coins in a piggy bank = 100 + 50 + 20 + 10

= 180

(i) Number of 50 p coins = 100

Probability of getting a $50 \mathrm{pcoin}=\frac{\text { Number of favourable outcomes }}{\text { Number of total possible outcomes }}$

$=\frac{100}{180}=\frac{5}{9}$

(ii) Number of Rs 5 coins $=10$

Probability of getting a Rs 5 coin $=\frac{\text { Number of favourable outcomes }}{\text { Number of total possible outcomes }}$

$=\frac{10}{180}=\frac{1}{18}$

Probability of not getting a Rs 5 coin $=1-\frac{1}{18}$

$=\frac{17}{18}$